[PATCH] mm: fadvise: avoid signed integer overflow calculating offset

From: Sasha Levin
Date: Mon Dec 01 2014 - 23:04:38 EST


Both offset and len are signed integers who's overflow isn't defined. Use
unsigned addition to avoid the issue.

Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
---
mm/fadvise.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/fadvise.c b/mm/fadvise.c
index 3bcfd81d..762cb63 100644
--- a/mm/fadvise.c
+++ b/mm/fadvise.c
@@ -67,7 +67,7 @@ SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice)
}

/* Careful about overflows. Len == 0 means "as much as possible" */
- endbyte = offset + len;
+ endbyte = offset + (u64)len;
if (!len || endbyte < len)
endbyte = -1;
else
--
1.7.10.4

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